<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            width: 200px;
            height: 200px;
            border-radius: 50%;
            background: #fff;
            box-shadow: 2px 2px 5px 2px #000 inset;
            /* （水平阴影，垂直阴影，模糊距离，阴影大小，颜色，内阴影 */
        }
    </style>
</head>

<body>
    <div></div>
</body>

</html>